NOTE: The original source of the data in this
table, the American Association of Port Authorities, notes that the metric
tons used for the rankings are estimates from various sources, including the
individual seaports, and are based on cargo weights, volumes, and units. As
such, the figures cannot be converted into a single standardized measure such
as TEUs. Because of this, the estimates are also not directly comparable
across all seaports.

SOURCE: U.S. Department of Transportation, Research
and Innovative Technology Administration, Bureau of Transportation
Statistics, based on data from American Association of Port Authorities. Port Industry Statistics.
World Port Rankings:2007, available at www.aapa-ports.org as of
Sept. 30, 2009.

By weight, 7 of the world's top 10 seaports in 2007 were in China. Three U.S. ports-South
Louisiana, Houston, and New York/New Jersey-ranked among the top 25